Some existing toy vehicles having pneumatic engines have detachable pressure vessels for storing fluid. The pressure vessel is removed from a toy vehicle and pressurized by a separate pump. Once pressurized, the pressure vessel is reattached to the toy vehicle for powering the engine. Constant detaching and reattaching of the fluid pressure vessel can lead to degradation of the joint between the pressure vessel and the toy vehicle. A poor joint between the pressure vessel and the toy vehicle leads to a loss of pressurized fluid within the pressure vessel, which results in a less powerful engine. When the joint has deteriorated sufficiently, the entire toy vehicle must be replaced to attain the same degree of performance as when the toy vehicle was new. Moreover, since the pressure vessel is detachable, it is easily lost or misplaced. Without the pressure vessel, the toy vehicle is inoperable and the missing vessel must be replaced.
Other existing toy vehicles have integral fluid pressure vessels, but still require a separate pump to pressurize the pressure vessel. The pump is connected to the pressure vessel to pressurize the pressure vessel. The pump must be disconnected from the pressure vessel to use the toy vehicle. Therefore, one must remember to bring the corresponding pump for the toy vehicle or the pressure vessel cannot be pressurized, which results in the toy vehicle being inoperable. Furthermore, repeatedly connecting and disconnecting the pump to and from the pressure vessel can lead to degradation of the connection between the pump and pressure vessel, thereby increasing the difficulty of pressurizing the pressure vessel. Once the joint has deteriorated sufficiently, the entire toy vehicle must be replaced to attain the same degree of performance as when the toy vehicle was new. As with the detachable vessel, the pump may be easily misplaced or lost, again resulting in the toy vehicle being inoperable and requiring replacement of the pump.
Thus, there is a continuing need to provide improved toy vehicles having integral pumps and pressure vessels.